KR100365781B1 - CHANNEL MANAGEMENT METHOD OF VoIP SYSTEM - Google Patents

Abstract

The present invention relates to a channel management method in a voice over internet protocol system. The present invention relates to a method for allocating a corresponding channel when a call setup request from an endpoint is received, and to performing an immediate response test to the allocated channel. Or determining the destination system state and selectively attempting a TCP / IP connection over the network according to the identified state.

Description

CHANNEL MANAGEMENT METHOD OF VoIP SYSTEM}

The present invention relates to a Voice over Internet Protocol (hereinafter referred to as "VoIP") system, and more particularly, to a channel management method for preventing channel blocking due to network fail.

Voice over Internet Protocol (VoIP) is a new type of communication service that makes voice calls through the Internet network, rather than making voice calls through PSTN (Public Switch Telephone Network). Unlike the conventional method, the call method using the internet network uses a packet-based network, so that voice calls can be made more cheaply without paying a domestic / international telephone line fee. VoIP can send not only audio but also video information using the H.323 protocol, an ITU-T standard.

The VoIP system using the Internet network as a back-bone is configured as shown in FIG. Referring to FIG. 1, the VoIP system includes the Internet 8 used as a backbone, and the Internet 8 is connected with gateways 6 and 10 and personal computers 16 and 18. Each of the gateways 6 and 10 is connected to the PSTNs 4 and 12, which are connected to the telephone terminals 2 and 14, respectively. Terminals such as telephone terminals 2 and 14 and PCs 16 and 18 have the ability to communicate by voice (required), video (selection) and data (selection) during 1: 1 communication or conference. Is an endpoint. Such a terminal may perform real-time two-way communication with the gateway 6 and 10 and other terminals. The gateways 6 and 10 are connected to the Internet 8 or terminals (e.g., PCs 16 and 18) connected to a packet based network and to PSDNs 4 and 12 or an Integrated Services Digital Network (ISDN). The terminal (for example, the telephone terminals 2 and 14) is a component that enables real-time two-way communication.

The VoIP system as shown in FIG. 1 performs a TCP connection (Transmission Control Protocol connection) for the first time regardless of any protocol such as H.323, Simple Internet Protocol (SIP), or Media Gateway Control Protocol (MGCP).

A procedure of call setup in a VoIP system is described below with reference to FIGS. 2 and 3. 2 is a communication protocol diagram of a caller side for explaining a channel management method in call setup according to the prior art, and FIG.

The setup request message Q931_setup_req msg is sent from the end user via the PSTN 4 to the gateway 6 by a call setup request from the end user 2, for example. Is passed on. At this time, the PSTN 4 and the gateway 6 allocate channels corresponding to call setup. The gateway 6 attempts a TCP / IP connection to the other party's IP (Internet Protocol) address in response to a setup request message from an end user (TCP / IP connection req in FIG. 2, steps 100 and 102 in FIG. 3). At this time, if the other party's system, for example, the gateway 10 is down or there is a network fail, TCP / IP connection cannot be made. In this case, the gateway 6 will retry a continuous TCP / IP connection in about 30 seconds (somewhat different depending on the operating system (OS)) (steps 106 to 108 of FIG. 3). If there is no response from the other party (i.e. NAK) even after retrying the TCP / IP connection for about 30 seconds, the gateway 6 knows that the TCP / IP connection has failed. ) State is reached (step 112 of FIG. 3). On the other hand, if there is a response from the other party, the gateway 6 performs the subsequent steps of the call setup procedure (step 110 in FIG. 3).

On the other hand, the gateway 6 must continuously retry for 30 seconds if there is no response when requesting a TCP / IP connection (for this reason, 30 seconds is referred to as the default delay time of the OS). If the call setup request is attempted again without waiting for the 30 second period, the VoIP system cannot be used normally because the current channel is blocked. In addition, in a VoIP system having multiple channels, the gateway 6 may request a TCP / IP connection by allocating a new channel after 30 seconds. In this case, if there are many spare channels, this may not be a problem. However, in a VoIP system in which there are not many spare channels, all of the channels may be blocked if the user continues to attempt a call setup request.

Accordingly, an object of the present invention is to provide a channel management method for preventing channel blocking due to network failure in a VoIP system.

In accordance with the above object, the present invention provides a method for managing a channel in a voice over internet protocol system, the method for allocating a corresponding channel when a call setup request from an endpoint is received, and a test capable of immediately responding to the assigned channel. And a process of identifying a current network state or a destination system state and selectively attempting a TCP / IP connection over a network according to the identified state.

1 is a configuration diagram of a general VoIP system;

2 is a communication protocol diagram for explaining a channel management method in call setup according to the prior art;

3 is a control flowchart of a gateway at a call setup of the prior art;

4 is a communication protocol diagram for explaining a channel management method in call setup according to an embodiment of the present invention;

5 is a control flowchart of a gateway at call setup according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are represented by the same numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

In order to supplement the above problems of the prior art, it is best to always check the situation and destination of the network in the VoIP system. However, periodically testing a large number of destinations in a VoIP system and managing them as a database is a factor that degrades the performance of the VoIP system. In addition, increasing the performance of the Central Processing Unit (CPU) or adding new modules for periodic testing will lag behind price competition.

In an embodiment of the present invention, when a call setup request is received, a test is performed so that a current network state or a state of a destination system may be immediately recognized before attempting a TCP / IP connection. Therefore, if there is a problem with the state of the network or the destination system, try not to try TCP / IP connections to prevent channel blocking without introducing performance and cost issues such as system degradation or adding new modules. Make sure

4 is a communication protocol diagram illustrating a method of managing a channel during call setup according to an embodiment of the present invention, and FIG. 5 is a control flowchart of a gateway at call setup according to an embodiment of the present invention.

Hereinafter, a method of channel management during call setup according to an embodiment of the present invention will be described in detail with reference to FIGS. 1, 4, and 5. In the following description, it will be assumed that the telephone terminal 2 of FIG. 1 is a calling party endpoint, that is, an end user, and the gateway 6 is a calling party gateway.

As shown in Fig. 4, the setup request message Q931_setup_req msg causes the PSTN 4 to be disconnected from the telephone terminal 2 due to a call setup request from the telephone terminal 2, which is an end user. Is passed to the gateway 6. At this time, the PSTN 4 and the gateway 6 allocate channels corresponding to call setup.

When a setup request message is received from the end user (step 200 in FIG. 5), the gateway 6 performs a test to determine the network state or the state of the destination system with an IP address of the other party before attempting a TCP / IP connection. (Steps 202 to 212 of FIG. 5). The test is a "ping test" which is a test function used to check a delay time to a destination. In general, a "ping test" will respond within 500ms, so if you attempted a normal call setup, there would be very little delay due to the routing of the channel.

The "ping test" performed by the gateway 6 to grasp the network state or the state of the destination system will be described in more detail with reference to FIG. 5. When the setup request message is received from the end user (step 200 in FIG. 5), the gateway 6 first requests a "ping test" request on the network of the currently allocated channel to the other party's IP (Internet Protocol) address (step 202 in FIG. 5). ). Thereafter, it is determined whether there is a response within 1 second from the destination corresponding to the counterpart's IP address (step 204 of FIG. 5), and if there is no response, a "ping test" request is attempted on the network (step 206 of FIG. 5). Thereafter, it is determined whether there is a response within 2 seconds from the destination corresponding to the counterpart's IP address (step 208 of FIG. 5), and if there is no response, the "ping test" request is retried on the network (step 210 of FIG. 5). Thereafter, it is determined whether there is a response within 3 seconds from the destination corresponding to the counterpart IP address (step 212 of FIG. 5). If there is no response in step 212 of FIG. 5, that is, there is no response to three "ping test" requests, the gateway 6 releases the channel (step 214 of FIG. 5), and also releases the channel in the PSTN 4. Send a message to No response to a "ping test" request means that the network conditions and the status of the destination system are not normal. In this case, in the embodiment of the present invention, the gateway 6 prevents the channel blocking phenomenon in advance by releasing the corresponding channel without requiring the TCP / IP connection.

On the other hand, if there is a response from the destination to the "ping test" request on the network in the determination of steps 204, 208, and 210 of FIG. 5, the gateway 6 recognizes that the network state and the state of the destination system are normal and the TCP / IP connection request (step 216 of FIG. 5) and the subsequent steps of the call setup procedure (step 218 of FIG. 5).

In the above description of the present invention, specific embodiments have been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, the present invention can prevent and minimize channel blocking or release time delay during call setup due to network problems or system problems in the VoIP system. As a result, there is an advantage that the channel can be efficiently used and managed in the overall VoIP system such as a VoIP endpoint, a VoIP gateway, and a gatekeeper.

Claims (6)

A channel management method in a voice over internet protocol system, Allocating a corresponding channel when a call setup request from an endpoint comes in; Performing a test capable of responding immediately to the assigned channel to determine a current network state or a destination system state; And selectively attempting a TCP / IP connection over a network according to the identified state. The method of claim 1, wherein the immediately responsive test is a ping test. A channel management method in a voice over internet protocol system, Allocating a corresponding channel when a call setup request from an endpoint comes in; Requesting a ping test on the network of the assigned channel with the internet protocol address of the call setup requested destination and determining if there is a response from the destination within a first time period; If it is not answered even if the first period has elapsed, requesting a ping test on the network of the assigned channel with the Internet protocol address of the call setup requested destination and determining whether there is a response from the destination within the second period; Requesting a ping test on the network of the assigned channel with the Internet protocol address of the call setup requested destination if the second period has elapsed, and determining whether there is a response from the destination within the third time period; And releasing the allocated channel when the third period elapses. 4. The channel management method of claim 3, further comprising: attempting a TCP / IP connection according to the setup request on a network if there is a response from the destination during the first, second, and third periods. . The method of claim 3 or 4, wherein the first, second, and third periods of time are several seconds. 5. The channel management method according to claim 3 or 4, wherein the first period is 1 second, the second period is 2 seconds, and the third period is 3 seconds.